Near diffraction limit high-brightness 850 nm tapered laser diodes

High-power high-brightness tapered laser diodes emitting at 850 nm have been manufactured, and the beam quality of near diffraction limit has been achieved. The beam propagation factor M2 is only 1.7 and the high brightness is up to 16.3 MW·cm-2·sr-1 when the output power is 200 mW, and the values change to 2.8 and 9.9 MW · cm-2 · sr-1 under 1 W output. The electro-optical properties of tapered lasers are discussed. We have also studied the influence of tapered section length on output power. The results reported in this paper may become a step forward to new applications of tapered laser diodes.